SLUUCR5A december   2022  – june 2023 LM74900-Q1

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
    1. 1.1 EVM Features
    2. 1.2 EVM Applications
  5. 2Description
  6. 3Schematic
  7. 4General Configurations
    1. 4.1 Physical Access
    2. 4.2 Test Equipment and Setup
      1. 4.2.1 Power Supplies
      2. 4.2.2 Meters
      3. 4.2.3 Oscilloscope
      4. 4.2.4 Loads
  8. 5Test Setup and Procedures
    1. 5.1 Power-Up and Power-Down With EN Control
    2. 5.2 Input Overvoltage Test
    3. 5.3 Overcurrent Protection Test
    4. 5.4 Output Hot-Short Test
  9. 6EVAL Board Assembly Drawings
    1. 6.1 PCB Drawings
  10. 7Bill of Materials (BOM)
  11. 8Revision History

5.2 Input Overvoltage Test

Use the following instructions to verify the overvoltage protection feature of LM74900-Q1.

  1. Remove the input 33-V TVS (D1) in case you want to set and test the input overvoltage threshold, which is greater than the breakdown voltage (40 V) of the TVS.
  2. Set the input supply voltage VIN to 12 V and current limit of 10 A.
  3. Turn ON the power supply and observe start-up of output voltage, HGATE, and DGATE.
  4. Slowly increase the input voltage to 40 V. Observe the HGATE going low and turn OFF the load switch FETs (Q2 and Q4) when the input voltage reaches overvoltage protection threshold of 37 V.
GUID-20221128-SS0I-NH02-5MVR-RHX5QKP4R1BW-low.png Figure 5-6 Overvoltage Protection